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Publication numberUS2705535 A
Publication typeGrant
Publication dateApr 5, 1955
Filing dateJun 24, 1950
Priority dateJun 24, 1950
Publication numberUS 2705535 A, US 2705535A, US-A-2705535, US2705535 A, US2705535A
InventorsWaterman Russell R
Original AssigneeWaterman Russell R
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Oil well heating method and apparatus
US 2705535 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

April 5, 1955 R. R. WATERMAN 2,705,535

on. WELL HEATING METHOD AND APPARATUS Filed June 24, 195o 2 shets-sheet 1 N V EN TOR. #K9/arman BY A April 5, 1955 R. R. WATERMAN OIL WELL HEATING METHOD AND APPARATUS 2 Sheets'heet 2 Filed June 24, V1950 IN1/EN TOR Mferma/v United States Patent O OIL WELL HEATING METHOD AND APPARATUS Russell R. Waterman, Lodi, Calif. Application .lune 24, 1950, Serial No. 170,116 16 Claims. (Cl. 1166-40) This invention relates generally to heaters suitable for use in oil wells. sirable to supply heat in a zone well below the normal oil level in the well in order to facilitate proper liow of oil from an oil producing strata. Apparatus used in the past for this purpose has not been satisfactory, particularly when applied to the deeper producing wells. Hot water heaters are subject to excessive heat losses and do not make available a sufficient amount of heat in the region where it is desired. In addition hot water heaters require considerable equipment to supply the hot water in the amounts desired. Steam heaters which have been used in the past have not been satisfactory particularly because it has been difficult or impossible to maintain live steam in the heating jacket. When a heater of this character becomes filled with condensate the efficiency and performance is greatly impaired.

It is a general object of the present invention to provide a novel method for heating oil producing wells. The present method is characterized by maintenance of live steam within the heating jacket, whereby maximum heating effect is secured in the region where the heat is desired.

A further object of the invention is to provide novel heating apparatus for oil producing wells, and which in particular will be relatively etlicient and of high capacity, and will enable adequate heating to facilitate oil production and proper pumping.

Additional objects and features of the invention will appear from the following description in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawing.

Referring to the drawing:

Figure 1 illustrates a heater incorporating the present invention and installed in an oil producing well.

Figure 2 is a side elevational detail in section illustrating the control orifice employed in the heater of Figure l.

Figure 3 is a side elevational view in section illustrating a modilication of Figure 1.

Figure 4 is an enlarged cross-sectional detail illustrating the flow controlled orifice incorporated in Figure 3.

Referring to Figure 1, I have shown an oil producing well having the usual casing 10, and which has been equipped with the pumping tube 11. The lower end of the tube 11 connects with the barrel of a suitable pumping apparatus, such as one of the sucker rod type. According to customary practice the pump barrel is installed well below the normal oil level, and the plungers of the pumping apparatus connect with the sucker rod 12, which is reciprocated by suitable apparatus located at the surface of the well.

Well below the normal oil level I provide a heating jacket 13, which can be cylindrical in form and arranged to embrace a section 11a of the tubing. The upper end of the jacket is connected with a steam supply pipe line 14. This pipe line extends to the surface of the well where it is connected with a suitable source of steam under pressure. For this purpose I prefer to use a high pressure boiler of the ash type. Suitable steam ilow indicating means is also connected to the pipe line 14 at the surface of the well. Thus I have shown a metering orifice 16, which can be used in conjunction with the pressure gauges 17 and 18, to indicate the rate of steam ilow.

A condensate pipe line 19 also connects with the jacket 13, and extends upwardly to a point above the normal In many oil producing wells it is de- 2,705,535 Patented Apr. 5, 1955 oil level. A downwardly Iturned pipe portion 21 is shown connected to the upper end of pipe line 19, and the pipe line is also shown provided with a check valve 22 to prevent backflow of oil from the well.

The lower end of the condensate pipe line 19 connects with an orice fitting 23 (Figure 2) which is located near the lower end of the jacket. This fitting forms a ilow restricting orifice 24, which communicates with the interior of the jacket through the screen or strainer 26.

The jacket 13 can be installed either above or below the cylinder of the pumping apparatus. As illustrated it is assumed that the tube section 11b forms the pumping cylinder of a suitable oil well pump. The necessary plungers and valves (not shown) of the pumping apparatus are installed in the cylinder 11b.

Operation of the apparatus described above, and the steps of the present method are as follows: In a typical instance the oil producing strata may be at a distance of say 1,000 feet from the surface of the Well, and the normal oil level may extend to say 300 feet above the producing strata, or about 700 feet below the surface. With such an installation the boiler should be capable of supplying steam at a pressure of the order of 275 to 300 p. s. i., and at a rate suicient to supply the heater requirements. The pipe 19 can have its upper end terminating about feet above the normal lluid level, or about 600 feet below the top of the Well. When steam is rst applied to the pipe line 14, all of it is condensed, and condensate accumulates in the jacket 13. As pressure builds up in the jacket the condensate flows through the orifice 24 and upwardly through the line 19, to be discharged into the well above the normal oil level. Assuming that the steam pressure and the steam supply are adequate, a condition is soon reached in which the condensate level falls to about the region of the orilice 24, and thereafter the orice passes steam together with all of the condensate. This condition is immediately observed by the operator by noting the pressure gauges 17 and 18. When steam starts to flow through the orifice 24 the steam consumption drops sharply, steam ow through the pipe line 14 is reduced, and. this is indicated by a sharp drop in the pressure differential between gauges 17 and 18. The apparatus is now functioning normally, and heat is eiciently transferred from steam through the walls of the jacket 13 to the surrounding oil. It is also transferred to the tubing 11, and to oil passing through the same. By occasional checking of the pressure gauges 17 and 18, the operator can make certain that the jacket is operating properly, and that live steam is being delivered to the jacket 13, for proper performance. The condensate delivered through the line 19 also transfers some heat to the surrounding oil, and the condensate discharged into the well from this line is hot water, which intermingles with the oil and likewise transfers some effective heat. Since the condensate line 19 is not extended to the surface of the deeper wells to which the invention yis particularly applicable, the pressure required to discharge condensate through the same is not excessive, and therefore an applied steam pressure of reasonable value can sufce to discharge condensate through the orifice 24 and pipe 19, and to overcome the flow resistance involved.

In the embodiment of the invention illustrated in Figures 3 and 4, the heater jacket 31 surrounds a section 32a of the pump tubing, and the heater is located below the barrel 32h of the pumping apparatus. Tube section 32a connects with a cross tube 33, which communicates with the exterior of the jacket on opposite sides of the same. The steam pipe line 34 connects with the upper part of the jacket, and the lower part of the jacket connects with a condensate line 36, through the orifice control device 37. Device 37 can be constructed as shown in Figure 4. It consists of a body 38 having an inner chamber 39 which is in communication with the lower inlet 41. An open or inverted bucket type iloat 42 is loosely and pivotally supported at 43 from the free end of the valve lever 44. This lever carries a hernispherical valve member 45, which cooperates with the valve seat 46. It is loosely retained by the depending rods 47 and is provided with upturned tabs 48 which engage and fulcrum upon the shoulder face 49. The

passage 51 through the seat 46 is in communication with the condensate line 36. The lever 44 carries a button or stud 52 which is adapted to engage the tab 53. It will be evident that when the bucket assumes a lower position the valve member 45 is open with respect to the seat. However when the bucket lifts, tab 53 presses upwardly upon the stud 52, to move the valve member to closed position relative to the seat.

The device 37 is constructed the same as an inverted bucket type steam trap, such as a trap of the type manufactured and sold under the trade name of Armstrong Operation is as follows: When the chamber 39 is filled with condensate the bucket assumes its lowermost position whereby the valve member 45 is open relative to the seat 46. Assuming now that condensate flows through the inlet 41, it is permitted to ow through the seat 46 and upwardly through the condensate line 36, without substantial restriction. When some steam enters the chamber 39 together with condensate, the steam initially tends to accumulate within the bucket, thus lending some buoyancy which tends to lift the bucket to move the valve member 45 toward closed position. Thus the positioning of the bucket is dependent upon the buoyancy imparted by presence of steam within the same, and this in turn serves to automatically control the positioning of the valve member 45, as in a steam trap. With such a device the orifice through the seat 46 is automatically restricted as the steam to condensate ratio of material entering the inlet 41 increases. Conversely as the steam to condensate ratio of material entering inlet 41 decreases, the valve member 45 automatically moves toward open position, to decrease the fiow restriction through the orifice 51.

In place of the particular device 37 which has been illustrated and described, I can employ other devices for automatic orifice control, as for example other types of bucket or float operated steam traps.

In order to provide a suitable mounting for the control device 37, it is shown clamped against the lugs 56 of the web 57, with its lower end seated within the tubular strainer 58. This strainer extends between the device 37 and the lower end cap 59 for the heater.

Except for operation of the control device 37, the apparatus of Figure 3 operates in substantially the same manner as Figure l. Automatic reduction of the effective cross-sectional flow area which is made possible by the ow control valve 47, tends to increase the change in the reading of pressure gauges 17 and 18 when a condition of normal operation is attained, as distinguished from the higher steam flow rates experienced when the apparatus is first being placed in operation.

It will be evident from the foregoing that I have provided an oil well heater which is capable of providing the desired amount of heat within that region of the well where the heat is desired, and where it will be of maximum effectiveness. An operator can make certain that live steam is being delivered to the heating jacket, and this condition can be maintained as long as it may be desired. The dumping of hot water condensate into the well from the condensate line 19 improves rather than impairs the effectiveness of the apparatus, due to the added heat which is supplied. The amount of this condensate is ordinarily small compared with the oil produc ing capacity of the well, and this water is eventually pumped out of the well together with the oil.

I claim:

l. A continuously operable bottom hole heater for oil wells comprising a heat transfer jacket having a closed chamber therein and an exterior diameter less than the interior diameter of an oil well casing in which the heater is to be used, said jacket being adapted to be positioned deep in the casing and adjacent an oil producing subsurface strata, a separate heating fluid supply line adapted to extend from ground level to said chamber, and a combined condensing and removal passage means between the chamber and the interior of the casing removed from the supply line, means forming a flow restricted orifice between the chamber and the inner end of said condensing and removal passage means and having a fixed area smaller than the cross-sectional area of the chamber and smaller than the cross-sectional area of the removal passage means, said orifice being at a level adjacent the bottom of the chamber, said fixed orifice having a capacity for passing condensate only slightly in excess of one capable of discharging all said condensate from the chamber, and a substantially free flow discharge opening at the outlet end of said removal passage means.

2. A bottom hole heater for oil wells comprising a heat transfer jacket having a chamber therein closed to the fiow of production liuid and an exterior diameter less than the interior diameter of an oil well casing in which theheater is to be used, said jacket being adapted to be positioned deep in the casing and adjacent an oil producing sub-surface strata, a separate heating fluid supply line adapted to extend from the ground level to said chamber and forming the only passage into said chamber, a spent heating fluid removal pipe adapted to extend between a lower part of the chamber and a fixed location above the chamber, a hydraulic flow restricting orifice adjacent the bottom of the chamber forming the only passage from the interior of the chamber to the exterior and comprising a passage between the chamber and the removal pipe, said flow restricting orifice having a fixed area smaller than the cross-sectional area -of the chamber and smaller than the cross-sectional area of the removal pipe, and a free flow discharge passage at the upper end of the removal pipe.

3. In an oil well heating system the combination of a casing extending into the well to a location below production fluid level, a pump line in the casing extending to a location below said fluid level and a bottom hole heater comprising a heat transfer jacket having a chamber therein closed to the flow of production fiuid and having an exterior diameter less than the interior diameter of an oil well casing in which the heater is to be used, said jacket being adapted to be positioned deep in the casing leaving a clear space between the jacket and the casing and adjacent an oil producing sub-surface strata, a fluid supply line of cross-sectional area small relative to the cross-sectional area of the chamber adapted to extend from the ground level to the chamber, said supply line being separate from the pump line and lying between the pump line and the interior wall of the casing, a spent fluid removal pipe adapted to extend between the chamber at a location adjacent the bottom and a fixed location above the chamber, a constantly open restricted orifice adjacent to but removed from the bottom of the chamber forming a passage between the chamber and the lower end of the removal pipe, said restricted orifice having a fixed area smaller than the cross-sectional area of the removal pipe and smaller than the cross-sectional area of the chamber and adapted to admit discharge of said condensate, said restricted orifice being adapted to determine the depth of a condensate reservoir at the bottom of the chamber, and a free fiow discharge passage at the upper end of the removal pipe substantially greater in area than the restricted orifice.

4. A bottom hole heater for oil wells comprising a heat transfer jacket having a chamber therein for condensate and an exterior diameter less than the interior diameter of an oil well casing in which the heater is to be used, said chamber being closed to the ow of production liuid, said jacket being adapted to be positioned deep in the casing leaving a clear space between the jacket and the casing and adjacent an oil producing sub-surface strata, a separate fluid supply line for heating fluid only and of cross-sectional area small relative to the crosssectional area of the chamber, said supply line being adapted to extend from the ground level to the upper portion of said chamber, a condensing and removal pipe of small cross-sectional area compared to the chamber adapted to extend between the lower end of the chamber and a fixed location above the chamber and above the strata a distance sufficient to allow free outflow of condensate, a restricted orifice adjacent the bottom of the chamber forming an outlet from the chamber to the removal pipe, said restricted orifice having a fixed area sufficient to pass slightly more than all said condensate and having a location above the chamber bottom adapted to determine the depth of a condensate reservoir at the bottom of the chamber, and a free flow discharge orifice at the upper end of the removal pipe substantially greater in area than the removal pipe.

5. A bottom hole heater for oil wells comprising a heat transfer jacket having a chamber therein for condensate and an exterior diameter less than the interior diameter of an oil well casing in which the heater is to be used, said jacket being adapted to be positioned deep in the casing leaving a clear space between the jacket and the casing and adjacent an oil producing subsurface strata, a hot fluid supply line of diameter small relative to the diameter of the chamber adapted to extend from the ground level to the upper portion of said chamber, said line having a pressure differential gage therein above said ground level, a condensate removal pipe of diameter small compared to the chamber adapted to extend vertically at one side of the jacket and between a lower part of the chamber and a fixed location above the chamber and above the strata a distance sufficient to allow free outflow of condensate, a restricted orifice above the bottom of the chamber forming a passage from the chamber to the lower end of the removal pipe, said restricted oritice having a fixed area sufficient to pass all said condensate plus a small percentage of hot fluid and adapted to determine the depth of a condensate reservoir at the bottom of the chamber, a free flow discharge orifice at the upper end of the removal pipe substantially greater in area than the restricted orifice, a passage vertically through the jacket from a point below the bottom of the chamber to the ground level adapted to pass a mixture of oil land condensate to said ground level, and a back chefk valve in said removal pipe adjacent the discharge ori ce.

6. A method of continuously heating oil wells during pumping for extraction of low gravity oil by use of a closed heating chamber comprising lowering the chamber into a well to a level adjacent an oil producing strata, passing live steam from the ground level down into the chamber at a relatively rapid rate such that the quantity of steam exceeds the amount thereof reduced to condensate and simultaneously venting the condensate through a discharge outlet to the interior of said casing at a point adjacent said oil producing strata, said venting from the chamber being at a lower portion thereof and at a fixed predetermined rate restricted to one very slightly exceeding the rate of accumulation of said condensate and continuing supplying live steam until some live steam is being vented from the chamber with the condensate, and then changing the rate of supply of live steam to a rate where a balance is maintained between the amount of steam supplied and the amount of steam condensed and condensing all the steam escaping with the venting of the condensate so that no steam passes into the well.

7. A method of continuously heating oil wells during pumping for extraction of low gravity oil by use of a heating chamber closed against flow of production fluid comprising lowering the chamber into a well to a level adjacent to and below the top of an oil producing strata, passing live steam from the ground level down into the chamber at a relatively rapid rate such that the quantity of steam exceeds the amount thereof reduced to condensate in the chamber and during passage thereinto and simultaneously venting the condensate from the chamber at a restricted rate to a free-flowing discharge outlet at a level above the top of the strata and below ground level, said venting from the chamber being at a lower portion thereof and at a fixed predetermined rate restricted to one approximately equal to the rate of accumulation of said condensate and continuing supplying live steam until some live steam is being vented with the condensate, then reducing the supply of live steam to a rate sufficient to balance the rate of condensation, condensing all the steam which is vented with the condensate and before discharge of the condensate into the well and finally pumping oil and condensate from the well past the heating chamber through a separate pump line while the reduced rate of live steam is being maintained to maintain the heating condition.

8. A bottom hole heater for oil wells extending to oil producing strata, comprising a heat transfer jacket having a chamber therein closed to the flow of oil, an independent steam supply line adapted to extend from ground level to the level of said strata and being adapted to be connected to the chamber, said jacket being adapted to be located deep in a well adjacent the level of oil producing strata, and an orifice fitting adjacent the bottom of the chamber and between the chamber and the exterior of said jacket, said fitting including a transverse partition and having a flow-restricting orifice through the partition, said orifice having a capacity sufiicient for passing simultaneously all the condensate resulting from the condensation of steam passed through said supply line to the chamber together with a quantity of steam not exceeding in weight more than a small fraction of the weight of CIK all the condensate, an elongated condensing line extending from the orifice to the interior of the casing and a free flow discharge passage at the outer end of the condensing line.

9. A bottom hole heater for oil wells extending to oil producing strata, comprising a heat transfer jacket having a chamber therein, said chamber being closed to the flow of production fluid from the well, an independent steam supply line from ground level tot the level of said strata and being connected to the/ jacket, an elongated vertically extending condensing and removal pipe having an inlet end at the bottom of the pipe communicating with the chamber at the bottom of the chamber, and an orifice fitting between the chamber and the inlet end of the removal pipe, said fitting including a transverse partition'and having a flow restricting orifice through the partition having a maximum effective cross-sectional area less than the area of the removal pipe on the outlet side of the orifice, said orifice having a capacity sufcient for passing simultaneously all the condensate resulting from the condensation of steam passed through said supply line to the chamber together with a quantity of steam not exceeding in weight more than a small fraction of the weight of all the condensate, said removal pipe having a condensing portion thereof between the orifice and the outlet, said outlet being in direct communication with the interior of the well.

l0. A continuously operable bottom hole heater for oil wells wherein a casing has been sunk to oil producing strata, comprising a heat transfer jacket having a chamber therein adapted to be located in the well throughout the depth of the strata, a separate steam supply line from ground level to the level of said strata, said steam supply line being adapted to be connected at its lower end to the chamber, a vertically extending condensate removal pipe having an inlet at the bottom end cornmunicating with the chamber at the bottom of the chamber, said pipe having a length extending beyond the jacket, and an orice fitting between the chamber and the inlet end of the removal pipe, said fitting including a transverse partition and having a flow-restricting orifice through the partition, said orifice having a capacity sufficient for passing simultaneously all the condensate resulting from the condensation of steam passed through said supply line to the chamber together with a quantity of steam not exceeding in weight more than a small fraction of the weight of all the condensate, and a substantially free flowing discharge opening at the outlet end of the removal pipe. 11. A bottom hole heater for oil wells wherein a casing has been sunk to oil producing strata and a continuously operable pump line has been extended into the casing, said heater being continuously operable during pumping operations and comprising a heat transfer jacket having a chamber therein for heating fluid only, a steam supply line from ground level to the level of the strata, said supply line being connected at its lower end to the upper portion of the jacket whereby to position said jacket deep in the well adjacent tlie oil producing strata, a vertically extending condensing and removal pipe hav-ing an inlet end communicating with the chamber at the bottom of the chamber, said pipe having a length extending through and beyond the jacket, and an orifice fitting between the chamber and the inlet end of the removal pipe, said fitting including a transverse partition and having a flow-restricting orifice through the partition of cross-sectional area smaller than the area of the removal pipe on the outlet side of the orifice, said orifice having a capacity sufficient for passing simultaneously all the condensate resulting from the condensation of steam passed through said supply line to the chamber and passing into the chamber together with a quantity of steam not exceeding in weight more than a small fraction of weight of all the condensate passing said orifice, and a substantially free flowing discharge opening at the outlet end of the removal pipe, said discharge opening being in direct communication with the interior of the casing and at a level above the level of the oil producing subsurface strata.

l2. A continuously operable bottom hole heater for oil wells having casings and pump lines extending to oil producing strata comprising a heat transfer jacket having a chamber therein, a steam supply line separate from the pump line adapted to extend from the ground level to the level of said strata and adapted to be connected at its lower end to said chamber, said jacket being adapted to be located deep in a well adjacent the level of the strata and to retain steam and condensate, an orifice fitting between the chamber adjacent the bottom thereof and the exterior of the jacket, said fitting including a transverse partition and a How-restricting orifice device through the partition, said orifice device having an opening therethrough, a seat around said opening, an orifice restrictor adapted to engage said seat in a position at least partially closing said opening and a oat in the chamber having a greater buoyancy in the presence of steam than in the presence of condensate alone, said oat being operably attached to the restrictor and the restrictor being responsive to movement of the float for moving to difierent positions with respect to the seat and the opening whereby an increase in the proportion of steam to condensate is adapted to diminish the effective area of the opening.

13. A continuously operable bottom hole heater for an oil well having a casing and a pump line therein extending to oil producing strata comprising a heat transfer jacket having a chamber therein, a steam supply line adapted to extend from the ground level to the level of said strata and adapted to be connected at its lower end to said chamber, said jacket being adapted to be located deep in a well adjacent the level of the strata and to retain steam and condensate therein, an orifice fitting between the chamber at the lower end thereof and the exterior of the jacket, said fitting including a transverse partition and a dow-restricting orifice device through the U partition, said orifice device having an opening therethrough, a seat around said opening, an orifice restrictor adapted to engage said seat in a position at least partially closing said opening and a float in the chamber having a greater buoyancy in the presence of steam than in the presence of condensate alone, said float being operably attached to the restrictor and the restrictor being responsive to movement of the float for moving to different positions with respect to the seat and the opening whereby an increase in the proportion of steam to condensate is adapted to diminish the effective area of the opening, and a condensing and removal line connected between the downstream side of the orifice and the interior of the well below ground level.

14. ln the heating of oil wells for extraction of low gravity oil by use of a closed heating chamber having a supply line thereto, a vent from the lower end of the chamber to the interior of the casing and a How-restricting orifice in said vent the method comprising lowering the chamber to a level adjacent oil producing strata, initially passing live steam from ground level through the supply line into the chamber at a selected rate until the quantity of steam supplied exceeds the amount condensed by the initial heating of the well and contents, and simultaneously venting the condensate into the casing through said orifice until the condensate is vented at a rate more rapid than 4it is formed and a quantity of steam escapes through the orifice at a lesser rute than the steam is supplied. then continuing supplying steam at a steady rate such that the amount of heat supplied by the steam balances the amount of heat absorbed by the well and condensing steam escaping from the orifice before the steam reaches the interior of the casing so that only condensate is discharged into the casing.

15. ln the heating of oil wells for extraction of low gravity oil by use of a closed heating chamber having a supply line thereto, a flow-restricting orifice therefrom adjacent the bottom of the chamber and a vent pipe extending from the orifice to the interior of the casing whereby low gravity oil therein is rendered less viscous so as to increase the rate of flow the method comprising lowering the chamber to a level adjacent oil producing strata, Iinitially passing live steam from ground level into the chamber at a selected rate until the quantity of steam supplied exceeds the amount condensed by the initial heating ot' the steam line, chamber, well and contents, simultaneously venting the condensate through the flowrestricting orifice into said vent pipe and continuing the supply of steam until the condensate is vented at a rate more rapid than yit is formed and a quantity of steam escapes through the orifice at a lesser rate thanV the steam is supplied, then continuing supplying steam at a rate only slightly exceeding the rate at which steam is condensed by an amount such that the amount of heat suppiied by the steam balances the amount of heat absorbed by the well and wherein excess escaping steam is reduced to a rate no faster than the vent pipe is capable of condensing and only condensate is vented into the well.

16. In the heating of oil wells for extraction of low gravity oil by use of a closed heating chamber having'a supply line thereto, a vent pipe extending therefrom at the bottom of the chamber and to the interior of the casing and a flow-restricting orifice at an inlet end of the vent pipe the method comprising lowering the chamber to a level adjacent oil producing strata, initially passing live stream from ground level into the lowered chamber at a selected rate until the quantity of stream supplied exceeds the aggregate amount condensed by the initial heating of the steam line, the chamber, the well and contents, venting the condensate during the initial heating into the casing through said orifice until the condensate is vented at a rate more rapid than it is formed and a quantity of steam escapes through the orifice, effecting Vreduction of the capacity of the orifice and then reducing the quantity of steam supplied to a rate exceeding the rate of condensation but by an amount such that the steam pressure in the chamber remains substantially constant, whereby the amount of heat supplied by the steam balances the amount of heat absorbed by the well, and finally effecting condensing of any steam in the vent pipe which escapes through the orifice to said vent pipe whereby only condensate is vented into the well.

References Cited in the file of this patent UNITED STATES PATENTS 48,994 Parry July 25, 1865 200,393 Harris Feb. 19, 1878 403,183 Firth May 14, 1889 760,304 Butler May 17, 1904. 1,012,777 Wigle Dec. 26, 1911 1,709,581 Johnson Apr. 16, 1929 1,714,647 Vaughn May 28. 1929 1,960,999 Kaye May 29, 1934 2,035,381 Abele Mar. 24, 1936 2,049,050 Cram July 28. 1936 2,094,038 Kernin Sept. 28, 1937 2,208,784 Armstrong July 23, 1940

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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2828821 *Feb 3, 1954Apr 1, 1958Waterman Russell ROil well apparatus
US2908331 *Apr 18, 1958Oct 13, 1959Brown Albert LHeater for oil wells
US2914124 *Jul 17, 1956Nov 24, 1959Oil Well Heating Systems IncOil well heating system
US3207219 *Aug 26, 1960Sep 21, 1965Mitchell Edgar LApparatus for oil well paraffin control
US3438437 *Jul 11, 1966Apr 15, 1969Christofferson Carl EdwardConvector type heat exchanger
US3520367 *Oct 28, 1968Jul 14, 1970Phillips Petroleum CoMethod of producing oil using steam condensate trapped in storage zone
US4446917 *Mar 12, 1979May 8, 1984Todd John CMethod and apparatus for producing viscous or waxy crude oils
US9388667Jun 21, 2013Jul 12, 2016Chevron U.S.A. Inc.Heating production fluids in a wellbore
WO2014205432A3 *Jun 23, 2014May 7, 2015Chevron U.S.A. Inc.Heating production fluids in a wellbore
Classifications
U.S. Classification166/302, 166/61
International ClassificationE21B36/00
Cooperative ClassificationE21B36/005
European ClassificationE21B36/00D